<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>块元素和行内元素</title>
  <style type="text/css">
    h2{
      background: #39F;
      width: 350px;
      height: 50px;
      text-align: center;
    }
    p{
      background: green;
    }
    strong{
      background: purple;
      width: 360px;
      height: 50px;
      text-align: center;
    }
    em{
      background: #FF0;
    }
    del{
      background: #CCC;
    }
  </style>
</head>
<body>
<h2>h2标签定义的文本</h2>
<p>p标签定义的文本</p>
<p>
  <strong>strong标签定义的文本</strong>
  <em>em标签定义的文本</em>
  <del>del标签定义的文本</del>
</p>
</body>
</html>